The Present Disclosure relates generally to board mounted connectors, and more particularly, to such connectors having improved compliant mounting pins that offer beneficial insertion and retention capabilities.
Many electronic devices utilize internal circuit boards for circuitry and as a platform upon which to mount integrated circuits, switches, components and the like, including connectors. These connectors are often surrounded with a conductive shielding member that takes the form of a cage to provide grounding and shielding against electromagnetic interference radiation, known as “EMI.” These shields may be mounted to the surface of the circuit board, such as by soldering, or they may be provided with a plurality of members in the form of mounting pins that extend downwardly therefrom and which are received in openings formed in the circuit board. These openings are formed as plated through holes, or “vias,” directly in the circuit board and have a conductive metal plating applied to their inner surfaces, or sidewalls. The pins are formed as compliant members and are known in the art as press-fit pins or compliant pins. These pins are larger in overall size than the holes and this dimensional difference permits the pins to firmly engage the sidewalls of the holes and thereby form an electrical connection between the cage and the circuit boards. In addition to their use with shielding cages, compliant pins may also be used with electrical connectors for the same mounting purpose, and may be used directly as terminal tail portions in both connectors and other electronic components, such as switches, integrated circuits and the like.
There are problems in the use of press-fit compliant pins and these problems include inadequate performance during insertion into and retention by a circuit board. The cross-section of some pins may be lacking in structural integrity such that those pins may bend or buckle when the pins are inserted into their associated through holes. If the pins buckle during insertion they will not be fully inserted into the holes and may deform more than expected. This lack of full insertion and/or excessive deformation negatively affects the electrical contact between the pins and the surrounding vias and requires the cage to be removed and replaced, but in doing so, the buckled configuration of the pins may give rise to the possibility of damage to the expensive circuit board.
Similarly, if the pins buckle during insertion, they may provide adequate electrical contact with the circuit board but their retention capability may be diminished to the point where the electrical contact becomes sporadic and intermittent after the device in which the cage is used proceeds through assembly, packing, shipping and installation at an end user. This intermittent contact may not be discovered until the product is placed into service at the end user or shortly thereafter, thereby necessitating return of the device to the manufacturer.
The Present Disclosure is therefore directed to a compliant pin having an improved structure that offers greater resistance to buckling.